There are several factors that can cause a motorcycle starter motor to delay or take longer than usual to crank the engine, even when the battery and wiring are in good condition. Here are a few possible reasons:
Starter motor issues: The starter motor itself may have internal problems such as worn-out brushes, a faulty solenoid, or a weak armature. These issues can cause the motor to struggle and take longer to turn over the engine.
Ignition switch problems: The ignition switch is responsible for supplying power to the starter motor when you turn the key. If the ignition switch is faulty or worn out, it may not provide sufficient power to the starter motor, resulting in a delayed or slow crank.
Fuel or air delivery issues: If there are problems with the fuel delivery system, such as a clogged fuel filter or a weak fuel pump, the engine may not be getting enough fuel to start quickly. Similarly, air intake issues, like a dirty air filter or a malfunctioning throttle body, can affect engine performance and cause slower cranking.
Engine compression problems: If the engine has low compression due to worn-out piston rings, damaged valves, or a blown head gasket, it will be more difficult for the starter motor to turn the engine over. This can result in a delay or slower cranking speed.
Mechanical resistance: Excessive mechanical resistance in the engine, such as a seized component or excessive friction, can make it harder for the starter motor to crank the engine. This can be caused by various issues, including worn-out bearings, tight piston rings, or inadequate lubrication.
Electrical resistance: Even if the wiring appears to be in good condition, there could still be hidden electrical resistance in the circuit. Corroded connectors, loose or dirty connections, or damaged cables can increase electrical resistance, making it more difficult for the starter motor to receive the necessary power.
If your motorcycle's starter motor is experiencing delays or slow cranking, it's best to have a qualified mechanic diagnose the issue. They can perform a thorough inspection of the electrical and mechanical components to identify the specific cause and recommend the appropriate repairs.